Windows Update / Background intelligence transfer service

I am not able to do the latest windows update because the BackgroundIntelligenceTransferService is not running. I get an error when I go to services.msc and try to manually start it.
I don't usually run IE (use Mozilla), but need to use IE for the updating

This is the first update Windows update I have tried since installing NOD32 and ZoneAlarm.
Any relation?? I tried to enable the BITS with ZoneAlarm disabled and NOD32 virus turned off - same results.

My system is: Windows XP (SP2); Spyware Blaster; Ad-aware; Spybot.
I have also installed and uninstalled MS Anti-Spyware Beta and Ewido. (No problems, I just didn't think they were doing anything for me that I wasn't covered for.)
I have ran CCleaner and Registry Mechanic.

I haven't noticed any problems until this, altho I don't normally use IE. I also have the google toolbar fir IE.

We can try a few more things like re-installing the BITS service. What I am trying to avoid having you do is a complete uninstall/reinstall of SP2. I have seen this problem before and have had success with the above. However, on a few rare occasions an uninstall/reinstall of SP2 was required.

Thank you for all of your input. You really put me on the right track. I tried your suggestions (except for the re-install of SP2) and still wasn't able to get BITS started. I found the following recommendation in "Discussions in Windows Update" and it worked for me.